Wave propagation in solar spicules
The linear magneto-hydrodynamics waves in a spicule embedded in the coronal environment is studied. We derive the governing dispersion equation in the case of axial flow. Steady flows change the frequencies of propagating waves because of induced Doppler shifts. We calculate the periods of fundamental, second and third harmonics of standing kink waves for the spicule length of 3500-9000 km being in the range 120-300 s, 60-150 s and 30-75 s, respectively. We also analyze the observational data obtained from Hinode/SOT and found the spicule is oscillating with a period of 300-500 s. We suggest that the oscillation is caused by the fundamental standing kink mode. © 2011 American Institute of Physics.